(Vestsi Akademii Navuk Belarusi)
SERIES OF CHEMICAL SCIENCES
Published by The Belaruskaya Navuka Publishing House, Minsk, Republic of Belarus
| Proceedings of the Academy of Sciences of Belarus (Vestsi Akademii Navuk Belarusi) SERIES OF CHEMICAL SCIENCES Published by The Belaruskaya Navuka Publishing House, Minsk, Republic of Belarus |
Summary: Peculiarities have been studied of a porous structure formation of a network-type aluminophosphate prepared in a system Al2O3--P2O5--H2O--R, where R is a structure-forming reagent (organic base). A nature of the structure-forming reagent has been shown to affect both the porous aluminophosphate crystallisation process and their structure formation. A formation of a number of intermediate met astable products is a peculiarity of the synthesis. The sequence of the intermediates transformation depends on the composition of the reacting gel and processing temperature.
Summary: Concentration constants of the exchange of 15 benzoic acid derivatives (nitro-, amino-, oxy-, halogen-, etc.) on a chloride-ion have been determined using intermediate exchange technique. The constants calculated are in the range of 6 · 10-1 ... 1 · 105 depending on a substituent type and position. Charge distribution has been calculated by AMI method. Influence of a substituent nature and charge distribution in anions on extraction ability has been considered. A sharp increase of extraction has been revealed in the case substituents in ortho-position.
Summary: Thin films of Sn dioxide doped with transition elements were obtained using a method of magnetron sputtering of Sn and that with corresponding transition metal additives followed by thermal oxidation of the film obtained. Film thickness, resistance and thermo-electrical properties have been measured vs. experimental conditions of the film preparation. Concentration limits of the doping elements have been determined in which electrical properties are changed substantially.
Kuvaeva Z.I., Azizbekyan O.P.
Investigation of Sr2+ ion transfer through emulsion liquid membrane. pp. 19--22
Summary: A possibility of ELM extraction of Sr2+ from water solutions has been investigated, the main regularities of the process have been established and optimal conditions of the Sr2+ extraction have been determined. The main factors affected mass transfer of these ions are discussed.
Komarov V.S., Repina N.S.
Carbon-mineral magnetic adsorbents. pp. 23--26
Summary: The results are reported of an investigation of adsorption-structure properties and wetting heat of carbon-mineral magnetic adsorbents. The nature of organic compound from which carbon is formed as well as an initial hydroxide structure have been shown to affect the changing of Vs, and Ss, parameters of the samples. A hydrophobisation of the sample surface has been determined to be accompanied by an increasing sorption capacity. The latter increases continuously as the content of carbonforming organic compound is growing. A heat of wetting reflects a hydrophobisation rate.
Shemetkova N.I., Ariko N.G., Kenigsberg T.P., Agabekov V.E.
Painting of polyvinyl alcohol films in iodine-containing solutions. pp. 26--30
Summary: Conditions of a polarizer preparation from polyvinyl alcohol have been investigated. The optimal conditions have been determined such as component concentrations (I2 and Kl), time and processing temperature.
Mikhailovskii Yu.K., Agabekov V.E., Astapovich I.V., Azarko V.A.
Filmforming properties and photochromism of 1'-hydroxyethyl-3',3'-dimethyl-6-nitrospiro(indolin-2,2'-[2H-1]-benzopiran). pp. 30--37
Summary: Photochromism of a thermal vacuum-deposited film of 1'-hydroxyethyl-3',3'-dimethyl-6-nitrospiro(indolin-2,2'-[2H-1]-benzopiran) (SPI-1) has been investigated in comparison with that of isopropanol solution of the dye. It has been shown that during UV-irradiation SPI-l is reversibly converted from a colourless form to a coloured one, photochromism quantum yield being by 2.3 times lower in film than in solution.
Dolidovich A.F., Akhremkova G.S., Tumysheva T.V.
Kinetics of the adsorption of aromatic hydrocarbon vapours on the activated carbon fiber. pp. 38--42
Summary: Adsorption of benzene, toluene and p-xylene on two samples of the activated carbon fiber "Busofit-T" of different porous structure has been investigated. Effective coefficients of internal diffusion and their dependence on physico-chemical properties of adsorbates and an adsorbent micropore size have been determined. Diffusion coefficient has been established to increase during adsorption of aromatic hydrocarbons of the same homologous series with molecule polarizability increasing and micropore size decreasing.
Bogdanov P.A., Ivanovskaya M.I., Orlik D.R.
Structure and properties of SnO2 and SnO2--Pd films prepared by sol-gel method. pp. 42--48
Summary: Transparent fine-granular SnO2 and SnO2--Pd films (SnO2 average particle size was 25--30 nm) have been obtained by annealing tin hydroxide sols stabilised with oleic acid. Structure of the films was investigated by TEM, ED an Moessbauer spectroscopy. The films obtained have been shown to have a partially reduced structure of SnO2-x. Sensors based on sol-gel films obtained possess high sensitivity to various gases.
Ivashkevich O.A., Tuzik A.A., Gaponik P.N.
Quantum-chemical investigation of a space structure of 1-vinyltetrazoles. pp. 48--52
Summary: The rotation barriers, conjugation energies and relative ratios of S-cis and S-trans(R)-confomers have been investigated for a series of 1-vinyl-5R-tetrazoles (R = H, CH3, t-C4H9, C6H5, NH2, I, CF3, NO2) by the SCF MO calculations in AMI and NMDO approximations in order to evaluate an influence of the nature and size of R on conformational equilibrium.
Komarov V.S., Repina N.S., Kosobutskaya N.F.
Synthesis and adsorption-structure properties of zirconium phosphate. pp. 53--57
Summary: Samples of zirconium phosphate have been synthesised by zirconium building up on colloid particles of aluminium hydroxide followed by H3PO4 or Na3PO4 treatment. Adsorption-structure properties of these samples have been studied and the samples containing built up zirconium phosphate have been shown to possess a good developed pore structure and specific surface. It has been established that structure parameters of zirconium phosphate are changed with carrier structure changing due to duration of hydroxide precipitation. Such pore phosphates can be used not only as ion exchangers but as catalysts of oxidising dehydratation and a number of other catalytic processes as well.
Talapin D.V., Kulak A.I.
Faradaic rectification of electrical signals of noise nature in model electrochemical systems. pp. 57--62
Summary: The Faradaic rectification effects induced by electric noises in model electrochemical systems have been studied. Responses of an electrode system for harmonic and noise signals have been compared. Noise signals show promise for a determination of electrode reaction kinetic parameters.
Sviridov V.V., Shevchenko G.P., Susha A.S., Fedutik Yu.A.
Chemical precipitation of nickel, chromium and iron by Ti (III) complexes in aqueous solution. pp. 62--68
Summary: A possibility to use Ti (III) complexes as a reductant for iron subgroup metals has been shown. The process is carried out in aqueous solutions in the presence of ammonia and acidic ligands under weakly alkaline conditions at a room temperature and is accompanied by a catalytic reduction of water. Rates of the both competing reactions depend substantially on a nature of the metal reduced. Properties of the metal powders formed have been investigated.
Summary: The interaction of ultrafiltration membranes of various types with poly-[N-(2-aminoethyl)acrylamide] solutions has been studied. The largest flux decrease due to a membrane fouling resulting from the polyelectrolite adsorption has been found for polyamide membranes. This effect can be used to produce membranes of a new type with a comparatively low molecular weight cut off values.
Tutaeva N.L., Belyakova M.D., Mozheiko F.F.
Effect of concentration of alkaline metals chlorides on properties of cured urea-formaldehyde resin. pp. 73--78
Summary: The effect of concentration of sodium, potassium and lithium chlorides on gelation time of urea-formaldehyde resin (UFR) at 100 °C has been studied and these salts have been shown to accelerate curing to a certain extent. Properties of the cured samples have been investigated by small angle scattering and adsorption technique. A structure with larger pores has been shown to be formed in the presence of the chlorides as compared to the initial sample. Structure parameters depend on a chemical nature of alkaline metal cation and on a salt content. A stability of UFR cured in the presence of different amount of the salts has been measured. Presence of the salts leads to enhancing water- and salt stability of curing products.
Summary: Sorption and migration characteristics of 137Cs and 90Sr have been determined in fen peat, quartz sand, kaolin and bentonite. An electrolyte effect on the radio nuclides sorption and diffusion in the given systems has been studied. Presence of stable isotopes of caesium and strontium in the porous solution has been revealed to affect 137Cs and 90Sr distribution and diffusion indices permitting for the effective diffusion index to increase by two orders of magnitude. 137Cs in the peat of technogenic contamination resulting from the Chernobyl NPP accident has been found to be mainly in an exchange form and under steady state conditions up to 75% of 137Cs can be transformed into water-soluble state for 8--12 months under effect of stable caesium chloride (0.2 g-eq/l).
Summary: Collective, foam-generating, and flocculating properties of polyacrylamide emulsions with primary aliphatic amines having amino-group at secondary and tertiary carbon atoms have been investigated.
Geller B.E., Prokopchuk N.R., Vecher E.I., Shcherbina L.A.
Investigation of thermal properties of polyethylene therephthalate-fibroine blends. pp. 88--94
Summary: Thermal properties of polyethylene therephthalate-fibroine (PET-FN) blends prepared by the polymers combined dissolution in dichloracetic acid and reprecepitation in a cold water have been investigated by DTA an DSC techniques. Glass transition (Tc) and melting (Tm) temperature, enthalpy of melting (DHm) and effective activation energy of thermal destruction (DEd) have been determined. Introduction of FN and PET results in decrease of Tm and DHm as well as crystallinity degree of the matrix polymer. The values of DEd decrease with increasing FN content. Increasing ammount of PET in the blend causes the similar effect. A limited compatibility of these polymers has been suggested.
Kurakevich L.A., Stefanyuk I.V.
Influence of different fusible additives on physical and chemical properties of powder groundless enamels. pp. 94--97
Summary: An influence of different fusible compounds on physical and chemical properties of glass enamels has been studied. Parameters of optimal glass enamel coatings are presented.
Bychko G.V., Grozhik V.A.
Phosphorous aluminosilicate glasses as semiconductor passivating coatings. pp. 97--100
Summary: Some properties (thermal expansion coefficient and corrosion resistivity) of glasses P2O5--Al2O3--SiO2 doped by oxides of Cu, Sn, Te, Cd, Mn, Ti, Ba, La have been investigated. It has been shown that glasses containing SnO2, MnO2 and CdO may be used as materials for preparation of semiconductor passivating coatings.
Summary: The review generalises literature data on isolation, structure and biological activity of 2-acylcycloalkane-1,3-diones. The given compounds are produced by plants of different types, by microorganisms and insects and show a wide spectrum of biological action, including antimicrobial, antifungal, kairomonal, etc.
List of papers contained in the Journal "Vestsi Akademii navuk Belarusi", Seriya Chimichnykh Navuk, 1996 pp. 120--123
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